• 한국전자파학회논문지
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• 제20권3호
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• pp.313-321
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• 2009

본 논문은 부 반송파를 사용하는 이동 가능한 다목적실용위성 소형 관제국의 하향 링크 채널 설계 내용을 기술한다. 먼저 전송 신호 방식을 해석한 후 이 해석 결과를 단계별로 적용하는 방법으로 하향 링크 채널을 설계하였다. 하향 링크 전송 신호인 실시간(real-time) 2 kbps 위성 상태 측정 데이터의 수신 임계 신호 대 잡음비와 위성 거리 측정 요구 성능을 만족하는 신호 대 잡음비 해석 결과를 적용하여 6.5 dB/K의 G/T를 갖는 소형 관제국의 하향 링크 채널을 설계하였다. 설계에 따라 구현된 소형 관제국의 G/T는 태양을 이용한 측정 결과, 6.62 dB/K가 됨을 확인하였다. 또한, 위성과의 연동 시험을 통해, 부 반송파를 사용하는 위성 상태 데이터 요구 수신성능을 만족하여 다목적실용위성 관제국의 하향 링크 채널로 적합하게 평가되었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.611-614
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• 2006

ITU-R 결의 122는 47/48GHz 대역에서 위성 우주국 수신기와의 주파수 공유를 위해 HAPS 지상국에 대한 전력 제한에 대한 연구를 요구하고 있으며, ITU-R 권고 SF.1481-1에서는 FSS 시스템과의 주파수 공유를 위해 HAPS 지상국의 안테나 방사 패턴의 사이드 로브 특성을 개선하도록 권고하고 있다. 이에 본 논문에서는 HAPS 및 GSO FSS 서비스 커버리지간 비현실적인 이격거리를 줄이면서 결의 122에서 요구하고 있는 HAPS 지상국에 대한 전력 제한 및 권고 SF.1481-1의 지상국 안테나 사이드 로브 개선 등을 고려한 지상국의 최대 허용 off-axis e.i.r.p. 레벨을 제안함으로서 HAPS 지상국과 FSS 위성 수신기간의 주파수 공유의 가능성을 보인다.

• Earthquakes and Structures
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• 제13권1호
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• pp.17-27
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• 2017

In this study, the characteristics of site amplification at seismic observation stations in Japan were estimated using the attenuation relationship of each station's response spectrum. Ground motion records observed after 32 earthquakes were employed to construct the attenuation relationship. The station correction factor at each KiK-net station was compared to the transfer functions between the base rock and the surface. For each station, the plot of the station correction factor versus the period was similar in shape to the graphs of the transfer function (amplitude ratio versus period). Therefore, the station correction factors are effective for evaluating site amplifications considering the period of ground shaking. In addition, the station correction factors were evaluated with respect to the average shear wave velocities using a geographic information system (GIS) dataset. Lastly, the site amplifications for specific periods were estimated throughout Japan.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.57-62
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• 1999

The study has been performed to estimated the quantity of ground water recharge using the DAWAST model for water balance analysis in the Youngsan & Sumjin watersheds. The mean safe yield of ground water is annually 41.3mm, corresponding to 85 $\times$106 ㎥ at the Naju station in the Youngsan watershed, and 76.6mm corresponding to 343 $\times$ 106 ㎥ at the Songjung station in the Sumjin watershed. It is remarkable because safe yield of ground water are estimated 44 to 64 % less than the quantities estimated in the other researches.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1065-1070
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• 2004

Recenlty, there are many cases that structures are constructed on soft ground in domestic. Generally in those cases, appropriate geotechnical techniques for the ground are needed. In this study, an example for ground improvement of OO railroad station construction site is introduced and analyzed. The ground conditions of this site which is soft ground are that N value is under 6, average depth and ground water table is 24.4m, GL-1.7. So, as a countermeasure technique for bearing reinforcement, Compaction Grouting System (CGS) method was applied on construction site. To estimate the application of CGS method, piezo cone penetration test and static pile loading test were carried out during the construction. Results of analysis show that CGS method for improving the bearing capacity of soft ground is applicable for the ground well.

• 한국컴퓨터정보학회논문지
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• 제16권4호
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• pp.225-233
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• 2011

본 논문에서는 다양한 전장 상황에서 무인지상로봇의 효율적인 운용을 위한 통제장치와 지상로봇의 개발 방법을 제안 한다. 제안하는 통제장치의 활용을 통해 지상로봇을 운용자가 원하는 장소로의 이동 또는 지상로봇에 탑재된 다양한 임무장비의 활용을 통해 부여된 임무를 수행하는 것이 가능하다. 제안하는 통제장치는 햅틱 장치를 이용하여 입력된 운용자의 지상로봇 플랫폼 및 임무장비 제어신호를 전송하여 원격에서 무인지상로봇의 동작을 정밀하게 제어하기 위한 시스템이다. 통제장치는 운용자의 입력을 받는 햅틱 장치, 무인지상로봇의 운용 상태를 확인할 수 있는 전시장치, 내/외부 데이터를 처리하는 정보처리장치 등으로 구성된다. 또한 통제장치를 통해 부여받은 임무를 수행하는 지상로봇은 항법처리 컴퓨터, 차량 플랫폼, 장애물 회피 컴퓨터, 통합주행 컴퓨터로 구성한다. 본 논문에서 제안하는 방법을 통해 실 개발된 통제장치를 통해 다수의 지상로봇을 운용하였으며 이를 통해 지상로봇과 통제장치의 효율성을 검증하였다.

• Earthquakes and Structures
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• 제6권1호
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• pp.1-18
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• 2014

The main focus of this paper is the analysis of the different components of the variability for strong ground motions recorded from earthquakes produced by the Vrancea subcrustal seismic source. The analysis is performed for two ground motion prediction equations: Youngs et al. (1997) and Zhao et al. (2006), recommended within the SHARE project for the Vrancea subcrustal seismic source and which are proposed in the work of Delavaud et al. (2012) and graded best in Vacareanu et al. (2013c). The first phase of the analysis procedure consists of a grading procedure. In the second phase, the single station sigma procedure is applied for both attenuation models in order to reduce some parts of ground motion models' variability produced by the ergodic assumption. The strong ground motion database which is used throughout the study consists of over 400 accelerograms recorded from 9 Vrancea intermediate-depth seismic events. The results of the single station sigma analysis show significant reduction of the standard deviations, especially in the case of the Youngs et al. (1997) attenuation model, which is also graded better than the other selected GMPE.

• 한국기계기술학회지
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• 제13권1호
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• pp.11-16
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• 2011

When the trains are passed the station, a serious force is applied to ground and the caused vibration is propagated to the area of the station by the ground and rocks. The caused vibration brings about the operation interruption of the equipment which is sensitive to the vibration, or will bring about the structural damage of the station. In this study, to investigate the vibrational evaluation of railway station by the train service, the vibration simulation was performed and analyzed the effect of the vibration isolating countermeasure. From the vibration measurement, all trains that passed through the station exceeded the vibration criteria. Therefore, the vibration isolating countermeasure was established and the vibration simulation was performed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.305-308
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• 2005

The COMS, Korea's first geostationary multipurpose satellite program will accommodate 3 kind of payloads; Ka-Band communication transponder, GOCI (Geostationary Ocean Color Imager), and MI (Meteorological Imager). MI raw data will be transferred to ground station via L-band link. The ground station will perform image data processing for raw data, generate them into the LRIT/HRIT format, the user dissemination data recommended by the CGMS. The LRIT/HRIT are disseminated via satellite to user stations. This paper shows the COMS LRIT data generation procedure based on COMS LRIT specification and its verification results using the LRIT user station.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.304-307
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• 2004

Satellite orbit determination using angles only data from single ground station is carried out. The KOMPSAT-1 satellite mono-pulse angle tracking data from 9-meter S-band antenna at KARI site in Daejeon are used for the orbit determination. Various angle tracking arcs from one-day to five-day are processed and the orbit determination results are analyzed. Antenna pointing data are predicted based on the orbit determination results to check the possibility of re-acquisition and tracking of the satellite signal. Normal satellite mission operations including orbit determination, antenna prediction, satellite re-acquisition and automatic tracking from predicted antenna angle pointing data are concluded to be possible when three-day angle tracking data from single tracking station are used for the orbit determination.